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Tuesday, August 23, 2016

One of my central tenets of number normalization in Lync/Skype for Business has always been:

"Lync/Skype for Business will not attempt to normalize a number that already has a plus sign at the beginning"

There are signs that this is no longer true, at least for customers running Skype for Business Server 2015 and the Skype for Business 2016 client (and even the Lync 2010 client). I was messing around with normalization rules last night and realized that my Skype for Business 2016 client (version 16.0.7030.1021 32-bit) WAS normalizing numbers that started with a plus sign. I later validated this with a Lync 2010 client against the same Skype for Business 2016 server. And a commenter below said he's pretty sure he did this with Lync Server 2013. So this means that either it has ALWAYS worked this way and I never realized it, or its something relatively new on the server-side.

I should clarify here and state that the normalization rule in question was specifically constructed to include a plus sign in the normalization pattern (as highlighted below):

This DOES NOT mean that the Skype for Business client will suddenly normalize all numbers that start with a plus. If your normalization rules do not include a plus sign, it will not normalize a number with a plus sign.

This also means that dialing contact phone numbers from Outlook can also be much more reliable, especially if an extension is entered. Before, if a user entered a contact phone number with an extension in Outlook using the "Phone number builder", it would format the number like "+1 (212) 555-1212 x 345". If you clicked this number, Lync would parse the "x" as a "9" and the number would come out in Lync like "+121255512129345" and would likely fail.

I have no idea how long this new behaviour has been available. It works on a Skype for Business Server 2015 environment with both Skype for Business 2016 clients and Lync 2010 clients. I don't have a Lync 2013 or older environment to test with. I tried to see if this behaviour extended to server-side normalization scenarios with no luck. I tried to change the destination phone number on an incoming call that started with a plus sign. It didn't work, which implies that this is a client-only thing. The MSPL workaround is still required.

If this is only new to me, then I apologize for wasting everybody's time. I've incorporated my new findings into the Lync Optimizer (as you would expect), because it does allow for several dialing scenarios to work better than before.

If anybody has any information on this or can test other versions of Lync server/client, drop me a line.

UPDATE (2016-Aug-24): Updated to clarify that a normalization rule has to explicitly look for a plus sign for this to work. Original post implied that any valid, matching normalization rule would be applied to a number that had a plus sign on the front. Also made changes based on further observations with older clients.

Wednesday, August 10, 2016

Almost every country in the world has a dedicated country code assigned to it for telephony purposes (see countrycode.org for a full list). There is one very large exception to this rule and that is countries in North America (US and Canada) and a good portion of the Caribbean. These countries all share the same country code of +1 and are collectively part of the North American Numbering Plan (NANP), which is managed by the North American Numbering Plan Association (NANPA).

A NANP number consists of the country code +1, a 3-digit area code, and a 7-digit subscriber number, often formatted like +1 (212) 222-3333. You'll sometimes see the +1 omitted from the number on business cards and websites that don't think globally.

Dialing numbers in North America is quite different from most places in the world. In the rest of the world, if you want to dial a long-distance or national number, you have to dial a national access code. In a lot of countries, this number is 0. However, in NANP countries, you have to dial 1 for long-distance/national numbers. That's right, you have to dial the actual NANP country code as the long-distance access code, which is unique among all other countries. Incidentally, the international access code is 011 (in many other countries, its 00).

"Connect me with the German Chancellor immediately! I have an idea for a new album!"

If you want to dial Canada from the US, or the US from Canada, or any of the Caribbean countries in NANP, you don't dial the international access code 011, you just dial the number as you would any other long-distance number. So, if I want to dial Toronto, Canada from Vancouver, Canada I would dial +1 416 555 1111. If I wanted to dial New York City from Vancouver, I'd dial +1 212 555 1111.

It gets even better. NANP area codes are allocated by a trio of over-caffeinated spider monkeys who press numbers on a giant keypad at random to assign a new area code (well, that's how it appears). There is no logical separation between area codes between any of the countries. For example, area code 646 is in New York, USA, 647 is in Ontario, Canada, and 649 is in the Turks & Caicos (Caribbean island nation). Click here for a current list of area code allocations in NANP.

These days, calls between the US and Canada are often priced identically to a domestic long-distance call. But calls to the NANP Caribbean countries are usually priced much higher, akin to dialing some very remote international destinations. Continuing the previous example, a US user that has signed up for Microsoft's Skype for Business Online PSTN Calling Plan can expect to pay $0.013 per minute (just over 1 cent a minute) to call area code 647 in Ontario, but would end up paying $0.583 (almost 45x more expensive) to $0.741 per minute to call area code 649 in the Turks & Caicos.

Since it is nigh impossible for a regular person to distinguish a Caribbean country from US/Canada based solely on the area code, it is easy for people to accidentally incur high phone charges when calling these countries.

He had an Apple watch long before anybody else. True trendsetter, even if it took 30 years.

Skype for Business administrators often want to prevent certain users from dialing these Caribbean countries, and it can be easily done with some fancy routing rules. Assuming you've already configured voice polices for national and international access, then you just have to modify the National level voice route to block Caribbean destinations. You could do some research to determine the Caribbean area codes, and create your own regular expression to block them, but I figure I should do SOMETHING useful with this post and provide you with that information.

This Skype for Business route number pattern will block all Caribbean countries that are part of NANP, except for the US Virgin Islands and Puerto Rico (which are often not priced much differently than US numbers, when calling from the US):

You may note that I've also made sure to exclude premium area codes like 900 and 976.

To make sure that people assigned an International voice policy can dial those Caribbean countries, your international route should include a pattern for North American numbers and look something like this:

^\+((1(?!(900|976))[2-9]\d\d[2-9]\d{6})|([2-9]\d{6,14}))$

If you REALLY wanted to get draconian and block calls to Canada from the US, and vice versa, you could use the following rules:

The above rules are formatted slightly differently from the ones that block Caribbean countries. The Caribbean rules show which area codes to BLOCK. The other rules show which area codes to ALLOW. Of course, I didn't roll these rules by hand, since there are tens of dozens of area codes allocated to each country, and do change from time to time. I used the super handy-dandy Lync Optimizer. As you might expect, these options are available in the Lync Optimizer via the "Treat as National" option (only shows for North American dial rules). You can select one of the following options with regards to dialing other countries within NANP:

In-Country Only - Treat all calls to NANP countries other than your own as international, even though users don't have to dial 011 to reach them. As such, users will have to be a member of a voice policy that allows international dialing.

US/Canada - Treat calls to anywhere in US/Canada as national calls, excluding the Caribbean. To dial Caribbean countries, users will have to be a member of a voice policy that allows international dialing. Not available for Caribbean rulesets.

US/Canada/Caribbean - Treats calls to anywhere in NANPA (US/Canada/Caribbean) as national calls (along with the potentially higher call costs).

If you are creating a ruleset for a Caribbean country that uses +1 as the country code, you won't be able to select US/Canada, since this would make dialing within that Caribbean country difficult.

Selecting the Simple Ruleset option prevents usage of this feature, and will default to US/Canada/Caribbean. You won't be able to control how people dial other NANP countries when there is only a single simple routing rule.

So, there you go. A lesson in the finer details of dialing numbers in North America that the rest of the world might not be aware of. Try to contain your excitement.

Monday, July 18, 2016

As SIP trunking becomes more reliable and trusted, companies are taking advantage of the ability to consolidate standard PSTN phone lines from multiple office locations into a single SIP trunk. Most of the larger SIP providers can provide phone numbers for multiple countries, allowing for even further consolidation of telephony resources.

Skype for Business is very well suited to this sort of consolidation. Typically, larger companies deploy large centralized Enterprise Edition pools in a few central datacentres that serve offices spread across entire continents. These centralized pools in turn connect to a SIP trunk over a trusted, secure connection.

As mentioned, these SIP trunks can provide phone numbers for multiple countries, and price those calls as if they originated from those countries. So, if a company has a SIP trunk in London, UK, they can give out phone numbers to other countries. For example, users could have Germany-based phone numbers served out of the London SIP trunk, and calls from those numbers would be priced as if they originated from Germany. If a German user placed a call to another German phone number, they would be charged as a local or national call, even though the SIP trunk may physically reside outside of Germany. Conversely, if that same German user called a London phone number, the call would be charged as an international call.

Setting up Skype for Business dial plans and voice policies in this situation can get tricky, but fortunately I've come up with a very clean and easy to execute plan on how this can be accomplished using the Lync (Skype) Dialing Rule Optimizer.

Let's use an example of a company with a central Skype for Business deployment in London, UK with a single SIP trunk assigned to that location. This company has offices in the following locations:

London, UK

Berlin, Germany

Paris, France

All user phone numbers for all three locations are hosted out of the London SIP trunk.

The company has the following requirements:

Users must be able to dial as they are accustomed to in their respective country

Must be able to limit dialing for certain groups to the local, national or international level for their respective country

Let's assume this is a greenfield deployment, and nothing has been done yet in terms of Enterprise Voice configuration outside of getting the London SIP trunk connected to Skype for Business.

The first thing to do is to generate rulesets for each of the three locations using the Dialing Rule Optimizer.

First, London:

Then Berlin:

Note that I selected the "Force English Rulenames", which I did just because I can't read German or French and would prefer English rule names and descriptions throughout my Skype for Business deployment.

And finally Paris...

The resulting .PS1 rulesets are then copied to one of the Skype for Business servers.

First, the London ruleset is applied to the deployment, creating user-level dial plans and voice policies when prompted. When complete, there will be a single London dial plan and 3 voice policies. All routes use the single SIP trunk (as you would expect, since its the only one available).

Dial Plan page after running London ruleset

Voice Policy page after running London ruleset

In this state, we can easily assign a UK dial plan and voice policies to UK users as appropriate.

Next, run the rulesets for Berlin and Paris. This is done for multiple reasons. Firstly, it will create German and French dial plans, so users in those countries can dial numbers as they do in those countries. Secondly, it will allow administrators to assign country-specific local, national and international policies. Someone assigned to a German national policy will only be able to dial phone numbers in Germany and nowhere else, regardless of the physical location of the SIP trunk.

When running the rulesets, make sure NOT to select the option to use least-cost routing. Least-cost routing only works with multiple SIP trunks from different providers. With a single SIP trunk, as in this example, implementing least-cost routing adds unnecessary PSTN usages to voice policies that ultimately don't accomplish anything. If we make a call from a German number to London using a London route, the call will still be billed as an international call from Germany, as the SIP provider will see the German number as the source and bill accordingly.

To make things easier and faster to run, I recommend the use of the multiple PowerShell command-line switches available with rulesets. It makes applying multiple rulesets faster and less prone to errors. For the rulesets in this example, I used the following switches (using the Paris ruleset as an example):

For a full listing of the available command-line options, use the command:

Get-Help .\FR-Paris-Lync.ps1 -Full

Once done, the dial plans and voice policies will look as below.

Dial Plan page after running Berlin and Paris rulesets

Voice Policy page after running Berlin and Paris rulesets

This might seem more complicated than absolutely necessary, and you would be right. You could certainly just use London-based rules for all locations, but it would limit your options severely.

Setting up things in this way will allow users to dial numbers exactly as they do at home, and also allows administrators very granular control over dialing capabilities. Common area phones in Paris can be limited to local dialing in Paris. First level helpdesk employees in Germany can be limited to dialing only German numbers.

This shows how easy it is to use the Dialing Rule Optimizer to quickly setup flexible dial plans and voice policies in even the largest voice deployments. If you have any questions about this method, please leave a comment.

Tuesday, March 8, 2016

For those who don't know, a trunk prefix is a number (or numbers) that typically has to be dialled prior to dialling a phone number within the subscriber's country, but outside the subscriber's home area code. The trunk prefix is a way to signal the telephone network that the dialed number is a long-distance or national-level call.

For example, the trunk prefix for UK national calls is 0. If I were sitting in Liverpool and wanted to dial someone in London, I would have to dial 0, then the area code for London (20), then the subscriber phone number (say 3456 7890). For example, 02034567890.

Not every country uses a trunk prefix, but those that do generally use 0 as a trunk prefix. The actual national trunk prefix usage breakdown (based on my research) is below:

101 countries don't use a trunk prefix at all

95 countries use 0

26 countries use 1 (these are countries that are part of NANPA, like US/Canada and many Caribbean countries)

Russia and 5 other former USSR states use 8

Mexico uses 01

Hungary uses 06

NANPA countries are unique in that the country code 1 is also used as a sort of trunk prefix for long-distance calls. Italy is another unique case in that they don't have a national trunk prefix, but they DO use 0 as the beginning of the area code, which can confuse people.

Trunk prefixes are NOT used outside of the country. Continuing my earlier example, dialling that same London, UK phone number from the US would start with my international call prefix (011), then the UK country code (44), the London area code (20), and finally the subscriber number (3456 7890), resulting in 011442034567890. If that US person tried to insert the UK national call prefix in the number (0114402034567890), it would fail to connect because trunk prefixes are not used outside the home country.

Now, the UK user shouldn't be expected to know the international trunk prefix for countries other than his own, so when presenting their number on business cards, web pages or emails, they should use the internationally recognized standard for phone number presentation, which is (DRUMROLL)......E.164!!!! Regular readers of my blog and anyone who knows Lync/Skype for Business should be intimately familiar with E.164 formatted numbers. If you need a refresher, look back at a very old (from 2010!), but still useful blog post on the subject.

The UK user should present their number like this:

+44 20 3456 7890

However, in many cases the UK user presents their number with the trunk prefix, like this:

+44 (0) 20 3456 7890

or

+44 (0) 203 456 7890

People within the UK understand what the (0) represents, but people outside the UK would assume the 0 is part of the phone number and try to dial it as shown, resulting in call failure. This particular practice is very common in the UK, France and to a lesser extent, Australia. There are likely others (please let me know). Below are some screenshots from various webpages from GLOBAL companies that exhibit this problem:

Astra Zeneca

BAE Systems

Rolls Royce

Since this blog sadly only reaches a very small percentage of the world's population, there's no way I can expect everyone to get their act together and format their phone numbers properly. Others have ranted about this exact practice before, and it hasn't seemed to help.

As you may be aware, when you're using Internet Explorer with the Skype for Business/Lync client plug-in, many phone numbers on web pages can be directly dialled by clicking the wee little Skype/Lync icon beside the phone number on the right. You can see this on the Astra Zeneca and Rolls Royce page samples above. You can click those icons, and it will dial the phone number as its presented on the page. Clicking the number for Astra Zeneca's media department will give you this:

This is not going to work for anybody, since the trunk prefix 0 will be dialled as part of the number and will fail. You might be thinking that you could write a normalization rule that could deal with this, but Lync/Skype for Business will not normalize a number that has a + in front, because it assumes that any number starting with a + is already normalized. No matter what you do, a phone number that already has the + can't be modified at the source.

If you're anywhere other than the UK, your international routes probably aren't so strict that it would "know" that putting the UK trunk prefix in the number is wrong, so Lync/SfB will happily send the call on through, only to get dumped by your PSTN carrier as an invalid number.

What you CAN do, is create a trunk translation rule that will catch any instances where a 0 is immediately after the country code and strip it before sending it to the PSTN. There are only a few countries where 0 is actually a part of the phone number (land line numbers in Italy and mobile numbers in the Republic of the Congo), so the regular expression we create can deal with this.

The first part of the expression with all the digits is the regex for every possible country code in the world. The (?:0) means that if 0 is present immediately after the country code, it will be dropped. Then we accept anything from 6 to 14 other digits. We separate out Italy (39\d), Republic of the Congo (242\d) to allow for 0 in the cases where they are allowed in those countries.

If you are located in a country that is guilty of the crime of not using E.164 formatted numbers everywhere (I'm looking at you, United Kingdom), then there is the additional step of modifying the appropriate voice routes to allow for numbers coming through the system with a 0 in the wrong spot. Using UK's national route as an example:

Note the presence of the 0? after the +44, which indicates that 0 may or may not be present for the route pattern to match. As of right now, the Optimizer will create modified routes only for countries that I'm aware of that flaunt the E.164 rules on a regular basis:

UK

France

Australia

If there are others, please let me know, either directly or via blog comments.

All the above logic has been incorporated into the Lync/Skype4B Dialing Rule Optimizer, so if you are using that tool for creating your EV dialplans/routing, then you'll be covered.

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About Me

I'm the Lync Product Master at Event Zero and a Lync MVP. My specialties (surprise, surprise) include Lync and Exchange. I worked at Microsoft a long, long LONG time ago as a support tech, and am pretty sure they installed a chip in my skull during one of the awesome parties they had back then. To give you an idea on how long ago I worked at MS, the first product I supported was MS-DOS 6.2! I moved on to greener pastures shortly after Windows 95 hit the scene, but still look back with fondness at those carefree days. I can be contacted via email at klasko@lyncoptimizer.com.